univalve vs class Gastropoda

univalve and class Gastropoda both are nouns.

Word	Noun	Adjective	Verb	Adverb
univalve	Yes	Yes	No	No
class Gastropoda	Yes	No	No	No

univalve (noun)	class Gastropoda (noun)
a class of mollusks typically having a one-piece coiled shell and flattened muscular foot with a head bearing stalked eyes	snails and slugs and their relatives

univalve (adjective)	class Gastropoda (adjective)
used of mollusks, especially gastropods, as snails etc.